Nitromemantine (developmental code name YQW-36) is a derivative of
memantine
Memantine is a medication used to slow the progression of moderate-to-severe Alzheimer's disease. It is taken by mouth.
Common side effects include headache, constipation, sleepiness, and dizziness. Severe side effects may include blood clot ...
developed in 2006 for the treatment of
Alzheimer's disease. It has been shown to reduce
excitotoxicity
In excitotoxicity, nerve cells suffer damage or death when the levels of otherwise necessary and safe neurotransmitters such as glutamate become pathologically high, resulting in excessive stimulation of receptors. For example, when glutamate ...
mediated by over-activation of the
glutamatergic system
Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can synt ...
, by blocking
NMDA receptors
The ''N''-methyl-D-aspartate receptor (also known as the NMDA receptor or NMDAR), is a glutamate receptor and ion channel found in neurons. The NMDA receptor is one of three types of ionotropic glutamate receptors, the other two being AMPA and ...
.
Pharmacology
Like memantine, nitromemantine is a low-affinity voltage-dependent
uncompetitive antagonist at glutamatergic NMDA receptors, however nitromemantine selectively inhibits
extrasynaptic NMDA receptor Extrasynaptic NMDA receptors are glutamate-gated neurotransmitter receptors that are localized to non-synaptic sites on the neuronal cell surface. In contrast to synaptic NMDA receptors that promote acquired neuroprotection and synaptic plasticity, ...
s while sparing normal physiological synaptic NMDA receptor activity, resulting in less side effects and a greater neuroprotective action, as well as stimulating regrowth of synapses with prolonged administration. The discoverers of nitromemantine have demonstrated that the
amyloid-β peptide associated with Alzheimer's disease acts as an agonist at
α7 nicotinic acetylcholine receptors, chronic overstimulation of which then results in uncontrolled release of
glutamate
Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can syn ...
, and consequent excitotoxicity. By blocking extrasynaptic NMDA receptors, nitromemantine is able to largely prevent this excitotoxicity while minimising the side effects usually seen with less selective NMDA antagonists. The
nitrate
Nitrate is a polyatomic ion with the chemical formula . Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are soluble in water. An example of an insoluble ...
group of nitromemantine was found to bind to a second site on the extrasynaptic NMDA receptor which had previously been targeted with
nitroglycerin
Nitroglycerin (NG), (alternative spelling of nitroglycerine) also known as trinitroglycerin (TNG), nitro, glyceryl trinitrate (GTN), or 1,2,3-trinitroxypropane, is a dense, colorless, oily, explosive liquid most commonly produced by nitrating g ...
, and this double action is thought to be responsible for the increased effectiveness of nitromemantine.
See also
*
Memantine
Memantine is a medication used to slow the progression of moderate-to-severe Alzheimer's disease. It is taken by mouth.
Common side effects include headache, constipation, sleepiness, and dizziness. Severe side effects may include blood clot ...
*
Neramexane
Neramexane is a drug related to memantine, which acts as an NMDA antagonist and has neuroprotective effects. It is being developed for various possible applications, including treatment of tinnitus, Alzheimer's disease, drug addiction and as an a ...
*
Amantadine
Amantadine, sold under the brand name Gocovri among others, is a medication used to treat dyskinesia associated with parkinsonism and influenza caused by type A influenzavirus, though its use for the latter is no longer recommended due to wi ...
References
Adamantanes
Amines
Antidementia agents
NMDA receptor antagonists
Nitrate esters
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